class Test

	def main is shared
		s = 'aoeu'
		assert s[0:4]=='aoeu'
		assert s[0:3]=='aoe'
		assert s[0:2]=='ao'
		assert s[0:1]=='a'
		assert s[0:0]==''

		assert s[1:4]=='oeu'
		assert s[2:4]=='eu'
		assert s[3:4]=='u'
		assert s[4:4]==''

		assert s[0:-1]=='aoe'
		assert s[0:-2]=='ao'
		assert s[0:-3]=='a'
		assert s[0:-4]==''
		assert s[1:-1]=='oe'

		assert s[1:3:1]=='oe'

		assert s[:4]=='aoeu'
		assert s[0:]=='aoeu'

		assert s[:-1]=='aoe'
		assert s[:-2]=='ao'
		assert s[:-3]=='a'
		assert s[:-4]==''

		assert s[0:]=='aoeu'
		assert s[1:]=='oeu'
		assert s[2:]=='eu'
		assert s[3:]=='u'
		assert s[4:]==''

		# a step other than 1 is not current supported

		assert s[1:-1:1]=='oe'
		assert s[::1]=='aoeu'

		# out of range does not complain (convenient and like Python)
		assert s[0:5]=='aoeu'
		assert s[5:5]==''
		assert s[0:-5]==''

		# using slice in string substitution
		# this is tricky for the implementation because colon is also used to format strings like '[s:N]'
		assert '[s[1:3]]'=='oe'